SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '929614eab7987c1f2720419856abb38c98eabda73da789b58d546c1e1fbe0a92' 
  AND token = 'KeEG6ns/eMKZyk6yS1FYhQoyPq3UMjzpKZLCPvvbdGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}